The [sup.223]Ra massic activity was determined by live-timed anticoincidence
counting (LTAC) of the entire [sup.223]Ra decay chain, using a method that was previously applied at NIST to the [sup.229]Th decay chain .
In these experiments, CNET was complemented by triple-to-double coincidence ratio (TDCR) LSC and live-timed anticoincidence counting (LTAC).
Schultz, Liquid-scintillation-based anticoincidence counting of Co-60 and Pb-210.
Key words: anticoincidence counting; CIEMAT/NIST method; germanium-68; liquid scintillation counting; positron emitter; standardization; TDCR method.
2.3 4[pi] [beta] - [gamma] Anticoincidence Counting (LTAC)
The NaI (Tl) detector was gated on the 511 ke V region using a single channel analyzer and the total [gamma]-ray ([N.sub.[gamma]] and anticoincidence ([N.sub.AC]) count rates were recorded.
The uncertainties, given in parentheses, are expanded (k = 2) uncertainties based on the evaluated uncertainty components listed in Tables 4-7 for the respective techniques Technique [C.sub.A], [10.sup.6] Bq * [g.sup.-1] 4[pi][beta] - [gamma] anticoincidence counting 3.104(18) (LTAC) LS counting with the Triple-to-Double Ratio (TDCR) 3.141(25) method LS counting with the CIEMAT/NIST (3)H-standard 3.058(44) efficiencytracing method (CNET) Gamma-ray spectrophotometry with High Purity 3.2(9) Germanium (HPGe) detectors Table 4.
(i) Only events with an energy deposition in a single detector were accepted (anticoincidence
It allowed one to obtain the fraction of [alpha]-particles lost in the [.sup.6]LiF converter by signal summation from the first and the second detectors and application of coincidence and anticoincidence
The bundle of anticoincidence
cosmic ray guard counters, seen surrounding the central counter in the figure, eliminates some 95% of the residual background from the penetrating [[mu].sup.-] radiation, through electronic cancellation.